Emerging versatile telecommunications services enable communications devices to exchange data containers each having multiple components of different types. For example, a component may include data representing a text, an image, an audio signal, or a video signal. Sophisticated terminal devices for handling such services are evolving rapidly leading to multiple “generations” of terminal devices separated by a relatively short time.
With co-existence of multi-generation terminal devices, incompatibility issues arise. A terminal device transmitting a data container would generally be unaware of the characteristics and capability of the receiving terminal device (or receiving terminal devices in the case of multi-cast communications). This requires that a facility be provided to ensure proper detection of the content of the data container in its entirety or proper detection of specific components thereof, and to notify a recipient terminal device of any changes made to the original container, as described in co-pending U.S. application of Ser. No. 12/238,390, filed on Sep. 25, 2008, the contents of which are incorporated herein by reference.
In addition to the compatibility issue, communicating multiple components each optionally having respective attachments further increases exposure to malicious insertions, such as viruses. The exposure of containers to intrusion necessitate that a content-filtering facility be provided.
There is a need, therefore to provide a facility for content filtering, in addition to content adaptation, in a network providing versatile services.